The patch titled
Subject: mm/slab_common.c: work around clang bug #42570
has been added to the -mm tree. Its filename is
slab-work-around-clang-bug-42570.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/slab-work-around-clang-bug-42570.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/slab-work-around-clang-bug-42570.patch
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------------------------------------------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
Subject: mm/slab_common.c: work around clang bug #42570
Clang gets rather confused about two variables in the same special section
when one of them is not initialized, leading to an assembler warning
later:
/tmp/slab_common-18f869.s: Assembler messages:
/tmp/slab_common-18f869.s:7526: Warning: ignoring changed section attributes for .data..ro_after_init
Adding an initialization to kmalloc_caches is rather silly here
but does avoid the issue.
Link: https://bugs.llvm.org/show_bug.cgi?id=42570
Link: http://lkml.kernel.org/r/20190712090455.266021-1-arnd@xxxxxxxx
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slab_common.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/mm/slab_common.c~slab-work-around-clang-bug-42570
+++ a/mm/slab_common.c
@@ -1028,7 +1028,8 @@ struct kmem_cache *__init create_kmalloc
}
struct kmem_cache *
-kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init;
+kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init =
+{ /* initialization for https://bugs.llvm.org/show_bug.cgi?id=42570 */ };
EXPORT_SYMBOL(kmalloc_caches);
/*
_
Patches currently in -mm which might be from arnd@xxxxxxxx are
thp-fix-unused-shmem_parse_huge-function-warning.patch
lib-mpi-fix-building-with-32-bit-x86.patch
slab-work-around-clang-bug-42570.patch
mm-sparse-fix-memory-leak-of-sparsemap_buf-in-aliged-memory-fix.patch
waitqueue-fix-clang-wuninitialized-warnings.patch
lib-test_meminit-fix-wmaybe-uninitialized-false-positive.patch
coda-stop-using-struct-timespec-in-user-api.patch
proc-sysctl-add-shared-variables-for-range-check-fix-3.patch
